#include <iostream>
using namespace std;


/**
 * 给数据类型取别名
*/
int main(int argc, char const *argv[])
{

    // typedef number = int;
    typedef int number;
    number a  = 10;

    // using twoNum = double; C++17支持
    using twoNum = double;
    twoNum b = 10.5;

    cout << a << endl;
    cout << b << endl;
    /* code */
    return 0;
}
